When you look at a airport there’s either a green or red dot in the middle. What does this mean?
Green- VFR (Visual flight rules) conditions. More than 5 nautical miles visibility
Blue- MVFR (Marginal VFR) 2-5 (I think) nautical miles visibility
Red- IFR (Instrument flight rules) <2 nautical miles visbility
Remember you can still fly IFR in MVFR or VFR conditions, commercial aircraft legally have to always fly IFR
(Thanks to @ewanfleming for correcting me)